Analysts said this could cause problems for President Obama's key healthcare reforms, since the Republican victory removes the 60 seat majority enjoyed by the Democrats in the Senate. Analyst Jeffrey Holford at Jefferies International said:

The 60 seat majority in the Senate gave Democrats the power to force any policy through the Senate that they may wish, without the risk of the Republicans blocking the vote. Once Scott Brown is sworn in, that changes. Consequently, any further progress of the Obama Healthcare bill through the Senate could become more problematic.

If the market views a failure of the bill as likely it will be seen as a positive for the large cap pharmaceutical companies as the industry was helping fund the bill by at least $80bn over the next 10 years.

So GlaxoSmithKline is up 11.5p at £12.96 while AstraZeneca has added 22.5p to £30.90p. But the biggest riser in a falling FTSE 100 at the moment is Shire, 45p better at £12.74. Aside from the Senate vote, Shire is being boosted by analysts at JP Morgan who have moved from neutral to overweight and raised their price target from £13.45 to £14.50. They said the company's long term growth potential was still underappreciated by the market:

At the JP Morgan healthcare conference, management seemed more confident than ever about their long-term aspirational sales target (mid-teens growth from 2009-2015). In our view, this level of sales growth should translate into earnings growth of 20-30% - significantly above current consensus expectations in the mid-teens. Intuniv (guanfacine extended release, non-stimulant ADHD therapy) should be a key swing factor for earnings upgrades this year, with further upside possible from better Replagal share in Europe and/or higher Adderall XR earnings stream as the Citizen Petition [a form of US patent] may well continue to hold beyond 2010.